1. Field of the Invention
The present invention relates to a video game control technique whereby game images from the viewpoint of a simulated camera, for example a 3-dimensional images, are created and displayed on a display screen and, while varying the viewpoint of a simulated camera, the game is conducted by receiving reactions from a player who is responding to images displayed on the above-mentioned display.
2. Description of the Related Art
Coin-operated game machines, wherein a camera is affixed to an appropriate location on the game cabinet and this camera captures the image of a player, who is playing in front of a game scene displayed on the monitor, are already known. In such game machines, the player's movement is confirmed by image capture of a special detectable object mounted on the player (and suitable for being image-captured by the camera). With these game machines, movement of the human body is detected from the image of the detectable object which is image-captured by the camera, and the game proceeds, developing in response to that movement. In addition, coin-operated games are known in which one ultrasound transmitter and two ultrasound receivers are mounted on top of the player's head, an ultrasound pulse transmitted by the transmitter is reflected by the player's head and the head position is calculated from the propagation times of the ultrasound pulses received by each of the two receivers and the time difference between them. In these games, the viewpoint of a simulated camera, which is the reference for generating simulated 3-dimensional game scenes, is linked to the calculated head position.
In contrast, unlike the case of coin operated games, it is difficult to achieve home video games which provide game scenes having a feeling of realism, through linking the viewpoint of the simulated camera to the player's movement. For example, a fixed and invariable play area cannot be assured, as it can in the case of coin-operated games, so there is the problem of processing the varied background images included in the captured image according to place and time. Furthermore, there is a limit to how strongly a player can be urged to buy the special “detectable object” which, as mentioned above, is easily detectable in a captured image.